The Kallamedu Formation is an Upper Cretaceous (Maastrichtian) geologic formation located in the Ariyalur district of Tamil Nadu, India that forms part of the Ariyalur Group. It dates to the Maastrichtian of the Late Cretaceous. Dinosaur remains and petrified wood samples are among the known fossils recovered from this formation.Weishampel, David B; et al. (2004). "Dinosaur distribution (Late Cretaceous, Asia)." In: Weishampel, David B.; Dodson, Peter; and Osmólska, Halszka (eds.): The Dinosauria, 2nd, Berkeley: University of California Press. Pp. 593–600. .
Lithology The Kallamedu Formation likely represented a fluvial environment. It is composed of siltstones, clays and sandstones. The high organic carbon content of some of the rocks are consistent with a swamp.
Paleofauna
Dinosaurs Dinosaurs from the Kallamedu Formation Genus Species Material Notes Images Abelisauridae indet.Indeterminate. "Disassociated remains" and teeth. BruhathkayosaurusYadagiri, P. and Ayyasami, K. (1987). "A carnosaurian dinosaur from the Kallamedu Formation (Maestrichtian horizon), Tamilnadu." In M.V.A. Sastry, V.V. Sastry, C.G.K. Ramanujam, H.M. Kapoor, B.R. Jagannatha Rao, P.P. Satsangi, and U.B. Mathur (eds.), Three Decades of Development in Palaeontology and Stratigraphy in India. Volume 1. Precambrian to Mesozoic. Geological Society of India Special Publication, 11(1): 523–528. B. matleyi ilium and ischium, femur, tibia, radius and part of a vertebra (specifically a platycoelous caudal centrum). Remains no longer exist Initially described as a Theropod, it was reclassified as a Titanosaur. Carnosauria indet.?Indeterminate. "Fragmentary remains" Carnosauria was often used as a wastebasket taxon.?CamarasauridaeC. R. Narayana Rao and L. Rama Rao. 1930. Some dinosaurian vertebrae. Proceedings of the Indian Science Congress, Allahabad 17:329. Indeterminate.Vertebrae. Camarasaurids are not known from the Cretaceous.Fusioolithus F. baghensisDinosaur eggs.MegalosaurusLydekker, Richard (1877). "Notices on New and Other Vertebrata from Indian Tertiary and Secondary Rocks". Records of Geological Survey of India. 10: 41.M.sp.A partial tooth, length of 1.8 inches, antero-posterior diameter of 0.9 inches and transverse diameter of 0.4 inches. The tooth is almost similar to Megalosaurus in shape and size though the posterior border is straigher.Megalosaurus was often used as a waste basket taxon. SauropodaIndeterminate.R. Lydekker. (1877). Notices of new and other Vertebrata from Indian Tertiary and Secondary rocks. Records of the Geological Survey of India 10(1):30–43C. R. Narayana Rao and L. Rama Rao. 1930. The limb bones of a sauropodous dinosaur. Proceedings of the Indian Science Congress, Allahabad 17:330. "Fragmentary remains." ?StegosauriaIndeterminate. Misinterpreted sauropod bone. Other more plausible Stegosaur material is known from Cretaceous India. TitanosauriaIndeterminate. Solitary egg.TitanosauriaIndeterminate.Matley, 1929. The Cretaceous Dinosaurs of the Trichinopoly district and the rocks associated with them. Rec. Geof. Surv. India. Vol. 61 (4):337-349.Ten large sauropod bones, some of which could be identified as a humerus or femur, proximal end of a femur and scapula. All the bones pertain to the limbs.Similar in size to Bruhathkayosaurus. Troodontidae indet. Indeterminate. Two teeth (DUGF/52 and DUGF/168).Close morphological resemblance to Troodon
Crocodylomorphs Crocodylomorphs from the Kallamedu Formation Genus Species Material NotesImages Crocodilia Indeterminate Teeth. Simosuchus cf.S. sp. Teeth. Notosuchian Related to Simosuchus.
Turtles Turtle from the Kallamedu Formation Genus Species Material Notes Kurmademys K. kallamedensis Nearly complete skull. A Side-necked Turtle.Testudines Indeterminate Several fragmentary pieces of carapace and one vetebral element. Too fragmentary to compare with Kurmademys.
Fish Fish from the Kallamedu Formation Genus Species Material Notes Lepisosteidae Indeterminate. Scales. Similar scales are known from the Intertrappean Beds.
Amphibians Amphibians from the Kallamedu Formation Genus Species Material Notes Anura Indeterminate. Fragmentary ilium.
References